Nullity of a 3x3 Matrix

Problem

Compute the nullity of a 3x3 matrix: the dimension of its null space.

Compute the rank by Gauss-Jordan elimination with partial pivoting and return 3 - rank.

Hint

Count pivot columns and subtract from 3; each missing pivot is a free variable.

case 1

in: [[[1,0,0],[0,1,0],[0,0,1]]]

expected: 0

case 2

in: [[[1,2,3],[2,4,6],[0,0,0]]]

expected: 2

case 3

in: [[[0,0,0],[0,0,0],[0,0,0]]]

expected: 3

case 4

in: [[[1,0,0],[0,1,0],[0,0,0]]]

expected: 1

case 5

in: [[[1,1,1],[1,1,1],[1,1,1]]]

expected: 2

Starter codePython

def nullity_3x3(A):
    # Your code here
    pass

5 test cases · run your code against them in the editor